The present invention relates generally to separating two or more chemical components from a mixture. More particularly the present invention is directed to a process and apparatus for separating two or more chemical components from a mixture that involves the use of an induction heated screw mechanism.
The ability to remove organics and/or inorganics from waste materials using commercially available thermal dryer systems is limited by the temperature capabilities of such systems. Traditional thermal dryers, such as hot oil screw dryers (commonly referred to as “porcupine dryers”) are limited by the temperature that hot oil systems are capable of achieving. Normally the oil used in such hot oil heated drying systems can only be heated to a temperature around 600° F. and even at that, the dryers' operating temperatures can be appreciably less than the maximum temperature at which the oil can be heated due to heating efficiencies, heat transfer efficiencies and heat losses.
If a chemical component such has an organic and/or an inorganic that is to be removed from a mixture such as a waste material or a waste stream has a boiling point that is higher than the maximum operating temperature of a traditional thermal dryer, that chemical component cannot be removed from the mixture using a traditional thermal dryer. Since many organic contaminants that have boiling points that are near or above the maximum operating temperature of traditional thermal dryers are subject to environmental land ban restrictions, these types of waste materials cannot be effectively treated by processes that use thermal dryers. As a result, such waste materials are most often incinerated in hazardous waste incinerators. Specific examples of these kinds of wastes include refinery wastes (or similar materials) that have high boiling point organics such as polycyclic aromatic hydrocarbons (PAH's) that restrict their ability to be disposed in a landfill.
The following U.S. patents exemplify various systems and process that use inductive thermal screws: U.S. Pat. No. 3,642,135 to Borden, U.S. Pat. No. 3,821,106 to Borden, U.S. Pat. No. 5,385,749 to Serpelloni et al., U.S. Pat. No. 5,632,863 to Meador, U.S. Pat. No. 5,679,398 to Serpelloni et al., U.S. Pat. No. 5,710,360 to Self et al., U.S. Pat. No. 6,487,843 to Tomczyk, U.S. Pat. No. 6,840,712 to Satchwell et al., and U.S. Pat. No. 7,028,746 to Akers et al. The following published pending U.S. patent applications also exemplify various systems and process that use inductive thermal screws: 2002/0170696 to Akers et al., 2003/0228196 to Satchwell et al., 2008/0136066 to Taylor et al., 2009/0004318 to Taylor et al., 2009/0179064 to Lee et al., 2009/0249641 to Graham et al., 2009/0281202 to Eyster et al.
The present invention provides a method for separating two or more chemical components from a mixture that involves the use of an induction heated screw mechanism.